100
FXPQ50 PGUM 052207
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
807 AM ChST Thu Jun 6 2024

.Marianas Synopsis...
Satellite shows an upper-level low within the Tropical Upper
Tropospheric Trough (TUTT) northeast of Guam and east-northeast of
Saipan. Otherwise, partly cloudy skies and isolated showers will move
through the Marianas Waters today. Combined seas of 4 to 6 feet are
composed mainly of trade-wind swell and wind waves.

&&

.Discussion...
The TUTT will continue to be the major influence on our weather for
the next several days in the Marianas. The main area of upper-level
divergence has shifted south and west of us, allowing weather to
improve today. Showers will be slightly increased, but seem like they
will fall short of scattered coverage.

Probably around Monday, a more actively divergent part of the TUTT
will come by. This will allow a slight chance of thunderstorms to
return, along with a chance of showers later next week.

&&

.Marine...
Combined seas of 4 to 6 feet will diminish to between 3 and 5 feet by
Saturday. Meanwhile, trade winds of 10 to 15 knots will diminish to
around 10 knots around the same time. This will allow benign marine
conditions to continue, the only exception being that around Monday
we could get a moderate risk of lightning.

&&

.Eastern Micronesia...
Satellite imagery this morning shows convection is ongoing around
Pohnpei and Kosrae this morning, while Majuro is fairly quiet with
partly cloudy skies.

The fragment of convergence between Pohnpei and Kosrae will continue
scattered showers and isolated thunderstorms across Kosrae and
Pohnpei today, and then start to weaken over the next few days. This
will keep the potential for scattered showers at Pohnpei and Kosrae
through Friday, but allow the risk of thunderstorms to decrease. For
Majuro, expecting partly cloudy skies and isolated showers for the
first half of today, but satellite shows a cumulus field developing
east of the atoll, and models still support the ITCZ, which is still
active in the central Pacific, redeveloping near just south of Majuro
later today or tonight. Following this guidance, decided to go with a
30 percent chance of showers and a slight chance of thunderstorms
this afternoon for Majuro, and then increasing the potential for
showers up to 50 percent tonight.

Benign sea conditions and light and gentle trades are expected to
continue through at least early next week at Pohnpei and Kosrae. For
Majuro, gentle to moderate trades are expected through Friday,
becoming light to gentle this weekend into early next week with
benign seas conditions. Altimetry shows combined seas around 5 to 6
feet east of Majuro and 4 and 6 feet at Kosrae and Pohnpei.

&&

.Western Micronesia...
The TUTT has continued to drift southwest and is west of Yap Proper
and near Palau this morning, though convection around Palau has
decreased overnight and some of the cloud cover is decreasing. The
trade-wind trough near Chuuk as drifted westward and is now moving
into eastern Yap State, while trailing trade-wind convergence extends
eastward across Chuuk. These features are producing scattered
showers and isolated thunderstorms across most of the region.

Given the proximity of the TUTT and the approaching trade-wind
trough, scattered showers and isolated thunderstorms will continue
across Yap today and tonight. Scattered showers and isolated
thunderstorms at Palau overnight have decreased, but with clouds
decreasing on satellite and winds remaining light, island-effect
showers and thunderstorms are expected to develop over Palau and
nearby coastal waters later this afternoon. Showers should then
remain scattered at Palau tonight as the trade-wind trough east of
Yap Proper moves through. Winds are expected to remain light to
gentle through the weekend, so expecting more island-effect
convection to develop at Palau, and potentially Yap Friday
afternoon, but this may be extended to include the afternoon hours
of Saturday and Sunday, depending on cloud cover and the strength of
the winds.

For Chuuk, a trade-wind trough continues to push westward, the trade
convergence over Chuuk will slowly weaken. Still expect scattered
showers and isolated thunderstorms to continue through tonight, and
then showers are expected to become isolated Friday through Saturday,
before the next weak trough moves in.

Benign sea conditions are expected to continue across the region
through early next week. Buoys near Yap and Palau show combined seas
around 2 to 3 feet due to light swell and winds. Around Chuuk,
altimetry is showing seas around 3 to 5 feet. Winds are expected to
remain light to gentle across Palau and Yap, while moderate winds at
Chuuk will become gentle late this weekend.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...None.
MP...None.
Marianas Waters...None.
&&

$$

Marianas: Stanko
Micronesia: Schank